2017. december 18., hétfő

Today, 68 year ago (18th December 1949), David Alexander Johnston was born in Chicago, USA. He worked as a volcanologist for the USGS and was an enthusiastic, talented scientist, who dedicated his life to help protect people from volcanic eruptions. I wrote a memory of him in my Hungarian Tűzhányó (=Volcano) blog 3 years ago and promised to translate this post in English. Here you go in this special date!

English translation of the original blog post written in Hungarian in 19th May, 2014

It is not easy to write something on the 34th anniversary of the tragic eruption of Mt. St. Helens. Personally, this volcanic eruption gave me a specific, decisive experience. This is not only because of the volcanic eruption itself, but also because of the human story what is behind the volcanic event. The eruption provided a vividly descriptive example how such volcanoes can work, involving the complex, but very nicely reconstructed pre-eruptive magma chamber processes as well as the complexity of the volcanic eruptions and all of these yield important messages to volcanologists. But there are also many people around this story. Volcanologists, who forecasted that this long-dormant volcano could awaken soon; volcanologists, who worked hard in early 1980 to understand better what was going on in the volcano and tried to save people’s life. Chain of events, specific moments, quick decisions, what affected and changed the life of many people…

This was what David A. Johnston could see in the morning of 18th May 1980: “This is it!. Photo (left): Gary Rosenquist

It is pretty hard to forecast volcanic eruptions and I had to tell that it is simply impossible! This means that nobody could precisely tell which volcano, when it will erupt and how this event will occur. All three questions should be answered accurately to perform effective risk management. However, this does not mean that we have no chance to save people, this does not mean that volcanologists are bad scientists, this does not mean that volcanology is not able to understand volcanoes. Eruption forecasting improved significantly in the last decades, volcanologists work very hard and their decisions could save life of 10’s of thousands of people worldwide during volcanic crisis. Mt. St. Helens was one of the most attractive volcanoes of the Cascades in western U.S. It was dormant since 1857 and this was a long time for people around it to think that this is not a dangerous volcano and they enjoyed the beauty what she gave. However, a few volcanologists were in another opinion. Dwight Crandell and Donald Mullineaux published a report in 1978, where they argued that Mt St Helens was a potentially dangerous volcano and could erupt soon, likely before the end of the century…
The volcano started to awaken on 15th March 1980, ca. 2 months before the catastrophic eruption. The USGS volcanologists were sure that these preliminary signs meant that the eruption would occur well before the end of the century. But, it was not easy to communicate the potential danger to the public and to the decision-makers. People considered the volcano as a tourist attraction and they did not think that anything bad could happen. In addition, this was also the place what gave work for many people since decades. They had no experiences; they did not know how volcanoes work, they did not know the danger what was related to volcanoes. Finally, volcanologists were able to convince the decision-makers to close the surrounding of the volcano and create a red zone, where nobody could enter. That was an important step ahead…

David A. Johnston is sitting at the Coldwater II. observation point and describes every events occurred in the volcano. Photo: Harry Glicken

Don Swanson, a young volcanologist was working on the Mt St Helens since 1972. He measured deformation changes and was involved in the scientific team, which was monitoring the volcano day and night from the beginning of March 1980. On 17th April, a bulge was discovered on the northern flank of Mt St Helens and later it inflated in an average of 1.5 meter/day. This was something new, what was hard to understand at that time and David A. Johnston was one of the scientists who believed that this could result in a lateral blast, a kind of rare eruption mechanism what had occurred before at Bezymianny, a volcano in Kamchatka, in 1956. There was an observation point at Coldwater II, where Harry Glicken, a young graduate student was manning. He was describing every changes of the volcano for more than 2 weeks, but he had an appointment with Richard V. Fisher, a volcanologist professor at the University of California on 16th May. Don Swanson was scheduled to replace him, but it turned out that he had to meet a German graduate student (Gerhard Wörner, who became later a famous volcanologist, petrologist working at the University of Göttingen, Germany) on 17th May. Thus, he asked David A. Johnston to replace him in that evening and promised him that he would be at the observation point in the next morning. Dave told Swanson that “the weather is pretty nice, the volcano is calm and I will be sitting at the observation point and ready for further gas measurements”.
Dave Johnston, who conducted gas measurements even in the crater before, sat the observation point in the evening of 17th May. He was a volcanologist, who felt that in order to protect people, he had to take even risks to understand better what is going on in a volcano. He knew that there is a potential for a lateral blast at Mt St Helens, but he sat in front of the bulge in ca. 10 km distance and collected data about the volcano. Carolyn Driedger was with him late that evening and she planned to camp another ridge overlooking the volcano, but Dave told her to go home, he would stay alone overnight. He had to collect more observations even though he knew that the volcano could erupt any time and if it occurs then there will be no way to escape. Face to face with the volcano, with the bulge… Nobody could see a lateral blast eruption, nobody had an experience about it, but Dave knew that it would be devastating. There was a major responsibility fall on the shoulder of the volcanologists. The volcano was calm already for days and many people argued that there was no danger and they wanted to be back into the red zone. There was a very nice weather on early May 18, some people started to move to the volcano to enjoy the beauty and rest in this particular place of the Earth.
In the early morning of 18th May, Dave sent some data to the base operation. Don Swanson was just about leaving to replace him. He had a quick look at the seismograph and noticed that a sign of big earthquake appeared. He run to the phone to call Dave. He could still hear Dave’s last words: "Vancouver! Vancouver! This is it!”… and then, silence… What was the meaning of these last words? It was not a shout like ‘Hey, I will be killed…’! It was rather an excited short notice that it happened what he assumed… the lateral blast! “This is it…” – It is there, the superheated mixture of gas and ash, which will sweep him away in seconds… He did what he had to do. He collected data, he interpreted the observations and warn people that this volcano could be highly dangerous. He was there until the very late time… It could happen that Harry Glicken or Don Swanson or Carolyn Driedger sat the observation point. But, Dave was there, it was his fate… I think that they are real heroes. They work hard to understand how volcanoes work, they want to know what signs could precede volcanic eruptions and they even take risks to protect people from natural disasters although they know the best how dangerous it is. But this is his/her life to do this… Dave knew what could happen, but he sat the observation point – 10 km distance from the bulge! He knew that Harry and Don had important meetings and knew that it was not a good thing to be too many in that dangerous place. This video is dedicated in his memory:

I could meet three persons from this story and these meetings particularly influenced me. I could meet Don Swanson in Hawaii, where he was working as a chief of the volcano observatory. He has an enormous knowledge on volcanoes, a friendly, helpful person with delicate humour. I met Carolyn Driedger in Tenerife and we talked a lot about the importance of outreach activities. She realized how important it is after the eruption of Mt St Helens. People should know more about volcanoes and this is a key-point in risk management. It was my great pleasure to take part in the workshop what she organized in the Cities on Volcanoes conference and I could present our outreach activities as well as my idea and plan about a volcano park in Hungary. Finally, I could talk a lot with Gerhard Wörner in the Eifel who told me his memories what happened there, how he was involved in this story as a graduate student from Germany. I had a luck that I could meet them and I am very sorry that I could not meet Dave…
Today, in the 34th anniversary of the Mt St Helens, I would like to emphasize the work of the volcanologists. Many of them dedicate their life to understand better the nature of volcanoes and for this, they take even the risks. However, they undertake it, because they have to provide forecast as accurate as possible and during a volcanic crisis, they have to issue prompt decision to prevent people. These decisions should be based on solid scientific experiences, interpretation of analytical data and observations. Dave was enthusiastic to collect data even in the crater of the Mt St Helens and sat in front of the bulging slope of the volcano, although he knew very well how dangerous it is. In addition, they have to deliver their knowledge to the people; society should know more about nature, more about volcanoes! Nobody knows when the next big eruption will occur but the firing-tape is burning somewhere and society needs people, like Dave was...